Apparatus and method for image capture using image stored in camera

ABSTRACT

An apparatus for capturing an image using an image stored in a camera includes a lens system for optically receiving an image, an image signal processor for converting the received image into a preview image and generating a first-resolution image using the received image at predetermined periods, a first buffer for receiving the first-resolution image from the image signal processor and temporarily storing the received first-resolution image, a display for displaying the preview image received from the image signal processor and the first-resolution image received from the first buffer, and a controller for controlling the image signal processor to display the first-resolution image temporarily stored in the first buffer on the display upon receiving an image capturing signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to capturing a still image using images stored separately at predetermined times in addition to a preview image and, more particularly, to an apparatus and method for storing high-resolution images received at predetermined times in a first buffer and capturing a still image using the high-resolution images stored in the first buffer.

2. Description of the Related Art

An ordinary digital camera includes a lens system for forming an image of a subject on a film or a surface of an image sensor, and the image sensor for detecting the image formed by the lens system as an electrical signal. The film or the surface of the image sensor corresponds to an image surface of the lens system. A focus of the lens system varies in position according to a distance between the lens and the subject. Therefore, it is possible to capture or photograph images of various qualities according to changes in the position of the image surface, which is associated with a position of the subject.

A user photographs a desired subject in an image using a digital camera with the above-stated elements. In order to more easily take a picture of a desired subject, the user may use a preview image that provides an image of the subject in real time, to previously get hold of the image to be captured. The preview image is displayed on a display through the lens system in real time, and the user may easily take a picture of the desired subject while viewing the displayed preview image. A camera with the function of outputting a preview image on the display is the necessaries of life, playing an important role in multimedia communication required in the modern society.

An internal structure of a common camera outputting a preview image will be described with reference to FIG. 1 below.

FIG. 1 shows an internal structure of a conventional camera outputting a preview image. Elements of the camera include a lens system 101, an image sensor 103, a driver 111, an Image Signal Processor (ISP) 105, a display 107, and a controller 109.

Referring to FIG. 1, the lens system 101 optically receives an image of a subject, and includes at least one lens. The image sensor 103 converts the image of a subject optically received by the lens system 101 into an electrical signal. The ISP 105 processes the electrical signal received from the image sensor 103 on a frame-by-frame basis, and outputs a low-resolution image frame that is converted according to screen features (size, picture quality, resolution, etc.) of the display 107.

The display 107 displays the low-resolution image frame received from the ISP 105 on a screen, and the driver 111 moves the lens system 101 according to control of the controller 109. Although not shown in the drawing, the driver 111 includes a motor for providing a driving force, and a carrier for moving the lens system 101 forward and backward by the driving force. The controller 109 controls the driver 111 to move the lens system 101 to a focal position.

Now, a description will be made of a procedure for receiving and analyzing a preview image using the elements in FIG. 1.

When an image of a subject is optically received through the lens system 101, the image sensor 103 converts the optically received image of a subject into an electrical signal and provides the electrical signal to the ISP 105. The image of a subject received through the lens system 101 is continuously received in real time, and the image sensor 103 converts the received real-time image of a subject into an electrical signal, and provides the electrical signal to the ISP 105. The ISP 105 converts the received real-time image of a subject into a low-resolution preview image and displays the low-resolution preview image on the display 107. The user may monitor the received real-time preview image on the display 107.

Commonly, however, when a user captures an image while viewing a preview image, an image following the preview image is captured. If the subject is stationary, it doesn't matter even though an image is captured after the time the user intends to take a picture of the subject. However, in case of an image sensitive to motion, an unwanted image may be captured after the time the user intends to take a picture.

SUMMARY OF THE INVENTION

An aspect of the present invention provides an apparatus and method for reading an image stored in a first buffer as a captured image and displaying the captured image on a display, when a user inputs an image capturing signal independently of a preview image being displayed on the display.

In accordance with one aspect of the present invention, there is provided a method for capturing an image using an image stored in a camera. The method includes receiving an image and converting the received image into a preview image; generating a first-resolution image at predetermined periods and temporarily storing the first-resolution image in a first buffer; determining whether an image capturing signal is received; and if the image capturing signal is received, storing the first-resolution image temporarily stored in the first buffer in a separate storage space and displaying the first-resolution image on a display.

In accordance with one aspect of the present invention, there is provided an apparatus for capturing an image using an image stored in a camera. The apparatus includes a lens system for optically receiving an image, an image signal processor for converting the received image into a preview image and generating a first-resolution image using the received image at predetermined periods, a first buffer for receiving the first-resolution image from the image signal processor and temporarily storing the received first-resolution image, a display for displaying the preview image received from the image signal processor and the first-resolution image received from the first buffer, and a controller for controlling the image signal processor to display the first-resolution image temporarily stored in the first buffer on the display upon receiving an image capturing signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram showing an internal structure of a conventional camera outputting a preview image;

FIG. 2 is a diagram showing an internal structure of a camera using an image stored in a buffer according to an embodiment of the present invention;

FIG. 3 is a diagram showing an internal structure of a camera using images stored in a plurality of buffers according to an embodiment of the present invention;

FIGS. 4A and 4B are diagrams showing a process of taking a picture using a subject's image stored in a buffer according to an embodiment of the present invention;

FIG. 5 is a diagram showing a process of extracting a high-resolution image from among images received at different times according to an embodiment of the present invention; and

FIG. 6 is a flowchart showing a process of taking a picture using an image stored in a buffer according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of the present invention with reference to the accompanying drawings. The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

FIG. 2 shows an internal structure of a camera using an image stored in a buffer according to an embodiment of the present invention. The camera shown in FIG. 2 includes a lens system 201, an image sensor 203, an Image Signal Processor (ISP) 205, a display 207, a first buffer 209, a memory 211, a controller 213, a key input unit 215, and a driver 217.

Referring to FIG. 2, the lens system 201 optically receives an image of a subject, and includes at least one lens. The image sensor 203 converts the image of a subject optically received by the lens system 201 into an electrical signal. The ISP 205 processes the electrical signal received from the image sensor 203 on a frame-by-frame basis, and outputs a preview image that is converted into a low-resolution image according to screen features (size, picture quality, resolution, etc.) of the display 207. The ISP 205 generates high-resolution images at predetermined periods and provides the high-resolution images to the first buffer 209. That is, the ISP 205 generates an image corresponding to a predetermined period among received images, as a high-resolution image, and temporarily stores the high-resolution image in the first buffer 209. The low-resolution preview image displayed on the display 207 in real time and the high-resolution image stored in the first buffer 209 may vary in size, picture quality and resolution according to user settings.

The display 207 displays a preview image received from the ISP 205. If there is an instruction of the controller 213, the display 207 displays the high-resolution image temporarily stored in the first buffer 209 instead of displaying the converted image received from the ISP 205. If there are one or more high-resolution images, they may be displayed on a screen of the display 207 together or selectively.

The first buffer 209 temporarily stores the high-resolution image received from the ISP 205, and may store one or more high-resolution images according to user settings or a size of a storage space. The first buffer 209 provides the temporarily stored one or more high-resolution images to the memory 211 according to an instruction of the controller 213. The memory 211 stores one or more high-resolution images received from the first buffer 209.

The controller 213 controls the ISP 205, the first buffer 209, and the driver 217. If an image capturing signal is received, the controller 213 provides a converted-image output interrupt signal to the ISP 205, and provides the first buffer 209 with a signal for outputting one or more high-resolution images temporarily stored in the first buffer 209 to the display 207. Upon receiving such a signal, the first buffer 209 provides the temporarily stored one or more high-resolution images to the memory 211 and stores therein. The temporarily stored one or more high-resolution images may be stored all in the memory 211, or may be selectively stored in the memory 211 according to user selection. One or more high-resolution images stored in the first buffer 209 may be displayed on the display 207 without conversion, but one or more high-resolution images may be delivered back to the ISP 205 and then displayed after they are converted into low-resolution images according to screen features of the display 207.

The key input unit 215 provides an image capturing signal to the controller 213 through an input means such as a button, and the driver 217 moves the lens system 201 according to control of the controller 213. Although not shown in the drawing, the key input unit 215 may include a motor for providing a driving force, and a carrier for moving the lens system 201 forward and backward by the driving force.

The ISP 205 may include a first converter (not shown) for converting the received image into a preview image, and a second converter (not shown) for generating image data from the received image at predetermined periods.

The memory 211 is a nonvolatile memory, and may be an external memory.

FIG. 3 shows an internal structure of a camera using images stored in a plurality of buffers according to an embodiment of the present invention. The internal structure of the camera shown in FIG. 3 further includes a second buffer 219 in addition to the elements of the camera shown in FIG. 2.

Referring to FIG. 3, the lens system 201 optically receives an image of a subject, and includes at least one lens. The image sensor 203 converts the image of a subject optically received by the lens system 201 into an electrical signal. The ISP 205 processes the electrical signal received from the image sensor 203 on a frame-by-frame basis, and outputs a preview image that is converted into a low-resolution image according to screen features (size, picture quality, resolution, etc.) of the display 207. The ISP 205 generates high-resolution images at predetermined periods and provides the high-resolution images to the first buffer 209. That is, the ISP 205 generates an image corresponding to a predetermined period among received images, as a high-resolution image, and temporarily stores the high-resolution image in the first buffer 209. The low-resolution preview image displayed on the display 207 in real time and the high-resolution image stored in the first buffer 209 may vary in size, picture quality and resolution according to user settings.

The display 207 displays the preview image received from the ISP 205. If there is an instruction of the controller 213, the display 207 displays the high-resolution image temporarily stored in the first buffer 209 instead of displaying the converted image received from the ISP 205. If there are one or more high-resolution images, they may be displayed on the display 207 together or selectively.

The first buffer 209 temporarily stores the high-resolution image received from the ISP 205, and provides the temporarily stored high-resolution image to the memory 211 according to an instruction of the controller 213. The memory 211 stores the high-resolution image received from the first buffer 209. If a new high-resolution image is stored in the first buffer 209, the second buffer 219 stores a high-resolution image generated in the next period. If a high-resolution image is stored in the second buffer 219, the high-resolution image stored in the first buffer 209 is deleted. Thereafter, a high-resolution image generated in the next period is stored in the first buffer 209. If the high-resolution image is stored in the first buffer 209, the high-resolution image stored in the second buffer 219 is deleted. That is, if a new high-resolution image is received and temporarily stored, each of the first buffer 209 and the second buffer 219 delivers or deletes the high-resolution image stored in the opposite buffer.

The controller 213 controls the ISP 205, the first buffer 209 and the driver 217. If an image capturing signal is received, the controller 213 provides a converted-image output interrupt signal to the ISP 205, and provides the first buffer 209 with a signal for outputting one or more high-resolution images temporarily stored in the first buffer 209 to the display 207. Upon receiving such a signal, the first buffer 209 delivers the temporarily stored one or more high-resolution images to the memory 211 and stores therein. The temporarily stored one or more high-resolution images may be stored all in the memory 211, or may be selectively stored in the memory 211 according to user selection. One or more high-resolution images stored in the first buffer 209 may be displayed on the display 207 without conversion, but one or more high-resolution images may be delivered back to the ISP 205 and the displayed after they are converted into low-resolution images according to screen features of the display 207.

The key input unit 215 provides an image capturing signal to the controller 213 through an input means such as a button, and the driver 217 moves the lens system 201 according to control of the controller 213. Although not shown in the drawing, the key input unit 215 may include a motor for providing a driving force, and a carrier for moving the lens system 201 forward and backward by the driving force.

While the number of buffers is limited to two in the drawing, the number of buffers may increase according to user settings.

A process of capturing an image of a subject using the elements of the cameras shown in FIGS. 2 and 3 will be described below.

FIGS. 4A and 4B show a process of taking a picture using a subject's image stored in a first buffer according to an embodiment of the present invention.

FIG. 4A shows a scene where a preview image is received, in which a preview image corresponding to an image of a subject is output on the display 207 in real time using the lens system 201 of the camera. Since the preview image output on the display 207 is not a high-resolution image desired by the user, a low-resolution image converted according to screen features (size, picture quality, resolution, etc.) of the display 207 is output. Meanwhile, while the preview image is being output on the display 207, high-resolution images are generated and temporarily stored in the first buffer 209 at predetermined periods. The temporarily stored high-resolution images may vary in picture quality and size according to user settings, and the number of the temporarily stored high-resolution images may be subject to change according to a size of a storage space in the first buffer 209 where the high-resolution images are temporarily stored.

In the case where two buffers are provided as shown in FIG. 3, the second buffer 219 deletes the previously stored high-resolution image if a new high-resolution image is stored in the first buffer 209. Thereafter, if a high-resolution image generated in the next period is stored in the second buffer 219, the first buffer 209 deletes the previously stored high-resolution image.

FIG. 4B shows a result after an image capturing signal is input by an input means such as a button. If an image capturing signal is received from the user, the controller 213 provides a converted-preview image output interrupt signal to the ISP 205. Upon receiving the interrupt signal, the ISP 205 no longer delivers the converted preview image to the display 207. After that, the controller 213 provides the first buffer 209 with a control signal for outputting one or more high-resolution images temporarily stored in the first buffer 209 on the display 207. Upon receiving this signal, the first buffer 209 stores one or more images displayed on the display 207 in the memory 211, and displays the temporarily stored one or more high-resolution images on the display 207.

The controller 213 may select a user-desired image from among the one or more high-resolution images displayed on the display 207 before storing one or more images displayed on the display 207 in the memory 211 according to user settings, and may store only the selected image in the memory 211. Although not shown in the drawing, the controller 213 may directly display one or more high-resolution images stored in the first buffer 209 on the display 207 without conversion, or may display one or more high-resolution images after delivering the high-resolution images to the ISP 205 and converting them into low-resolution images according to screen features of the display 207.

FIG. 5 shows a process of extracting a high-resolution image from among images received in different periods according to an embodiment of the present invention. It is assumed in FIG. 5 that an image of a subject is received through the lens system 201 of the camera once every 0.1 second.

Referring to FIG. 5, one or more images 501 to 509 are sequentially received through the lens system 201 of the camera. The received one or more images 501 to 509 are all sequentially converted into low-resolution preview images according to screen features of the display 207 in the ISP 205 and then displayed on the display 207.

The ISP 205 generates high-resolution images at predetermined periods, and stores them in the first buffer 209. That is, an image 503 received at 0.2 second and an image 507 received at the ISP 205 at 0.4 second are converted into low-resolution preview images, and at the same time, high-resolution images are generated. The generated high-resolution images are temporarily stored in the first buffer 209. The number of temporarily stored high-resolution images is subject to change according to a temporary storage space of the first buffer 209. A new high-resolution image is temporarily stored as the newest high-resolution image and the previously stored high-resolution image is deleted at intervals of 0.2 second. In case of a camera with multiple buffers, the image 503 received at 0.2 second is first stored in the first buffer 209, and if the image 507 received at 0.4 second is stored later in the second buffer 219, the first buffer 209 deletes the image stored at 0.2 second. Thereafter, an image received at 0.6 second is stored in the first buffer 209 and then the image stored in the second buffer 219 is deleted. As described above, the number of buffers is subject to change according to user settings.

FIG. 6 shows a process of taking a picture using an image stored in a first buffer according to an embodiment of the present invention.

Referring to FIG. 6, an image is received through the lens system 201 in step 601. The image is received at the ISP 205 through the image sensor 203, and converted into a low-resolution preview image by the ISP 205. That is, the ISP 205 converts the received image into a low-resolution preview image according to screen features of the display 207, and delivers the low-resolution preview image to the display 207. The display 207 displays in real time the low-resolution preview image converted according to its screen features.

In step 603, the ISP 205 generates images at predetermined periods, and temporarily stores them in the first buffer 209. The image temporarily stored in the first buffer 209 is a high-resolution image, and one or more high-resolution images may be stored according to a size of a storage space in the first buffer 209. Since new high-resolution images should be sequentially stored with the passage of time, a new high-resolution image is stored in an empty space occurring after the first stored high-resolution image is deleted, in order to secure a storage space, thereby updating high-resolution images in real time.

In step 605, the controller 213 of the camera determines whether an image capturing signal is received. The image capturing signal is received through the key input unit 215. If no image capturing signal is received, the controller 213 returns to step 601 and repeats the process of converting the image received through the lens system 201 into a preview image. If an image capturing signal is received, the first buffer 209 stores the temporarily stored high-resolution image in the memory 211 according to control of the controller 213 in step 607. Thereafter, in step 609, the temporarily stored high-resolution image is output on the display 207.

If the number of high-resolution images temporarily stored in the first buffer 209 is one or more, one or more high-resolution images are first displayed on the display 207 so that the user may store only desired high-resolution images in the memory 211. The one or more high-resolution images temporarily stored in the first buffer 209 may be displayed on the display 207 after they are delivered back to the ISP 205 and then converted into low-resolution images according to screen features of the display 207.

In case of a camera with the first buffer 209 and the second buffer 219, if a new high-resolution image is stored in the first buffer 209 and then a high-resolution image generated in the next period is stored in the second buffer 219, the first buffer 209 deletes the previously stored high-resolution. If a high-resolution image is stored in the first buffer 209 in a period following the next period, the high-resolution image stored in the second buffer 219 is deleted.

As is apparent from the foregoing description, exemplary embodiments of the present invention display one or more high-resolution images temporarily stored in the first buffer on a display in various manners so that a user may select only desired images and store only the selected images in a memory separately, thereby securing a storage space.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. 

1. A method for capturing an image using an image stored in a camera, comprising: capturing an image through an image sensor; converting the captured image into a preview image to display the captured image on a display; processing image data that has been received through the image sensor at predetermined periods; temporarily storing the processed image data in a first buffer; and if an image capturing signal is received, storing in a separate storage space an image that was temporarily stored in the first buffer at a time of receiving the image capturing signal.
 2. The method of claim 1, wherein the preview image is converted into an image smaller than the image data by an image signal processor according to screen features of the display.
 3. The method of claim 1, wherein an image corresponding to the predetermined period among the received images is generated as the image data, and in order to temporarily store image data generated at the predetermined periods, new image data is stored and the first stored image data among one or more image data stored in the first buffer is deleted.
 4. The method of claim 1, further comprising: if new image data is generated in a particular period, storing the image data generated in the particular period in the first buffer and deleting image data that was stored in a second buffer; and if new image data is generated in the next period, storing the image data generated in the next period in the second buffer, and deleting the image data that was generated in the particular period and stored in the first buffer.
 5. The method of claim 1, wherein the image capturing signal is input using an input means mounted on the camera.
 6. The method of claim 1, wherein one or more image data may be stored in the first buffer according to a size of a storage space of the first buffer, and is stored separately in a memory that is the separate storage space, if the image capturing signal is received.
 7. The method of claim 6, further comprising, if the one or more image data is temporarily stored in the first buffer, selecting image data desired by a user and storing the selected image data in the memory.
 8. The method of claim 6, further comprising displaying the one or more image data stored in the first buffer on one screen together or selectively.
 9. An apparatus for capturing an image using an image stored in a camera, comprising: a lens system for optically receiving an image; an image signal processor for converting the received image into a preview image and generating image data from the received image at predetermined periods; a first buffer for receiving the processed image data from the image signal processor and temporarily storing the received processed image data; a display for displaying the image data; and a controller for controlling the image signal processor to store the image data stored in the first buffer in a separate memory upon receiving an image capturing signal.
 10. The apparatus of claim 9, further comprising: an image sensor for converting an image of a subject that is optically received by the lens system, into an electrical signal, and providing the image signal to the image signal processor; a memory for storing the image data temporarily stored in the first buffer; and a key input unit for providing the image capturing signal to the controller using an input means.
 11. The apparatus of claim 9, wherein the first buffer stores one or more image data according to a size of a storage space.
 12. The apparatus of claim 11, wherein in order to temporarily store image data generated at the predetermined periods, the first buffer stores new image data, and deletes the first stored image data from among the one or more image data stored in the first buffer.
 13. The apparatus of claim 9, wherein the camera further includes a second buffer, and if new image data is generated in a particular period, the image data generated in the particular period is stored in the first buffer and image data stored in the second buffer is deleted; wherein if new image data is generated in the next period, the image data generated in the next period is stored in the second buffer and the image data that was generated in the particular period and stored in the first buffer is deleted.
 14. The apparatus of claim 10, wherein the display displays one or more image data stored in the first buffer on one screen together or selectively.
 15. The apparatus of claim 9, wherein an image corresponding to the predetermined period among the received images is generated as the image data.
 16. The apparatus of claim 9, wherein the image signal processor comprises a first converter for converting the received image into a preview image, and a second converter for generating image data from the received image at predetermined periods.
 17. The apparatus of claim 9, wherein the memory is a nonvolatile memory.
 18. The apparatus of claim 9, wherein the memory is an external memory. 